<?php
/**
 * Created by PhpStorm.
 * User: fengsenhua
 * Date: 2019/2/12
 * Time: 12:11
 */

namespace app\api\service;


use app\lib\enum\ScopeEnum;
use app\lib\exception\TokenException;
use app\lib\exception\WeChatException;
use think\Exception;
use app\api\model\User as UserModel;
class UserToken extends Token
{
    protected $code;
    protected $wxAppID;
    protected $wxAppSecret;
    protected $wxLoginUrl;
    function __construct($code)
    {
        $this->code=$code;
        $this->wxAppID=config('wx.app_id');
        $this->wxAppSecret=config('wx.app_secret');
        $this->wxLoginUrl=sprintf(config('wx.login_url'),$this->wxAppID,$this->wxAppSecret,$this->code);
    }
    public function get(){
            $result=curl_get($this->wxLoginUrl);
            $wxResult=json_decode($result,true);
            if(empty($wxResult)){
                throw new Exception('获取session_key及openID时异常,微信内部错误');
            }else{
                $loginFail=array_key_exists('errcode',$wxResult);
                if($loginFail){
                    $this->processLoginError($wxResult);
                }else{
                    return $this->grantToken($wxResult);
                }
            }

    }
    private function grantToken($wxResult){
        //拿到openid
        //数据库查看，这是openid是否存在
        //如果存在，则不处理，如果不存在那么新增一条user记录
        //生成令牌，准备缓存数据，写入缓存
        //把令牌返回到客户端去
        //keky:用户携带的令牌
        $openid=$wxResult['openid'];
        $user=UserModel::getByOpenID($openid);
        if($user){
            $uid=$user->id;
        }
        else{
            $uid=$this->newUser($openid);
        }
        $cachedValue=$this->prepareCachedValue($wxResult,$uid);
        $token=$this->saveTocache($cachedValue);
        return $token;
    }
    private function saveTocache($cachedValue){
        $key=self::generateToken();
        $value=json_encode($cachedValue);
        $expire_in=config('setting.token_expire_in');
        $request=cache($key,$value,$expire_in);
        if(!$request){
            throw new TokenException([
                'msg' => '服务器缓存异常',
                'errorCode' => 10005
            ]);
        }
        return $key;
    }
    private function prepareCachedValue($wxResult,$uid){
        $cachedValue=$wxResult;
        $cachedValue['uid']=$uid;
        //scope=16代表App用户的权限数值
        $cachedValue['scope']=ScopeEnum::User;
        //scope=32代表管理员的用户的权限数值
        //$cachedValue['scope']=32;
        return $cachedValue;
    }
    private  function newUser($openid){
        $user=UserModel::create([
            'openid'=>$openid
        ]);
        return $user->id;
    }
    private function processLoginError($wxResult){
        throw new WeChatException([
           'msg'=>$wxResult['errmsg'],
            'errorCode'=>$wxResult['errcode']
        ]);
    }
}